Pre-Lab 3 Quiz: Lab 4- Preparation of Benzil from Benzoin

Name: _________________    Date:_______________

 

1.      Write the balance equation including nitric acid for the oxidation of benzoin to benzil and how many moles of nitric acid is required for each benzion mole? ( 10 pts).

 

 

 

 

 

 

 

 

2.      Why this reaction has to be carried out in a fume hood? (10 pts)

 

 

 

 

 

3.      The UV spectra of benzoin shows a peak at lmax EtOH (247) nm and move to higher  lmax EtOH (purple color) when  NaOH solution added to a ethanol solution of benzoin. Explain this absorption in terms of benzoin structure(10 pts)

 

 

 

 

 

 

  

 

    

4.      How many moles are in 4 g of benzoin? (10pts)

     

 

 

 

Ans:_____________

 

5.      What is the theoretical yield of  benzil starting with 4 g of benzoin? (10 pts)

 

 

 

 

 

 

  Ans: __________________